During the maturation of follicles and corpora lutea in the rabbit ovary the activity levels of oxidoreductases of glycolysis, citric acid cycle, glycerophosphate cycle, pentose phosphate shunt as well as the Δ5,3β-hydroxy-steroid dehydrogenase were studied in granulosa cells by histochemical technique. While the oxidoreductases of the glycolysis, the citric acid cycle and glycerophosphate cycle show continuously unvaried activities a remarkable increase was found regarding the activities of NADPH2-supplying enzymes and Δ5,3β-hydroxy-steroid dehydrogenase before resp. after ovulation. According to these relations the granulosa cells of rabbit ovary cannot produce progesterone prior to 8 hours after ovulation. Furthermore, the analysis of the sequence and the functional role of enzyme activation in the granulosa cells allows some conclusions about the mechanism of gonadotrophin action influencing the metabolism of steroid hormone producing cells.
The histochemical localization of some oxydative enzymes which catalize steps in the Embden-Meyerhof chain, hexosemonophosphate shunt and the citric acid cycle, was studied in normal human ovaries.
In contrast to the very low concentration and homogeneous distribution of enzyme activities of the citric acid cycle in the ovarian components, the theca interna of the developing follicle and the theca and granulosa lutein cells show extremely high levels of activities of TPN-specific and glycolytic enzymes.
Attempts were made to establish some relation between the findings mentioned above and the localization of hormone production. It was concluded that the synthesis of progesterone is located in the granulosa lutein cells while the formation of oestrogens takes place in the remaining ovarian components, which show a high activity of TPN-specific and glycolytic enzymes.
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